Known are optical nodes that switch signals between a number of incoming optical single-core fibers and a number of outgoing optical single-core fibers. Each single-core fiber connects the optical node with another optical network element. Within each incoming single-core fiber, an incoming optical signal may be present, which consists of different incoming optical wavelengths. Each optical wavelength may carry a respective data signal.
In order to switch a data signal with its respective incoming optical wavelength from one of the incoming single-core fibers onto one of the an outgoing single-core fibers, the optical node contains an architecture, in which                each incoming optical signal of an incoming single-core fiber is split by a corresponding optical splitter onto a number of wavelength selective switches, wherein each outgoing single core-fiber is connected to a corresponding wavelength selective switch.        
A wavelength selective switch then combines different optical wavelengths of different incoming optical signals received by the wavelength selective switch.
Thus, the fraction by which an optical splitter has to split an incoming optical signal is determined by the number of the outgoing single-core fibers. Furthermore, the number of ports, which a wavelength selective switch has to contain for receiving incoming optical signals, is determined by the number of the incoming single-core fibers.